Intermediate adapter, camera body and imaging system

ABSTRACT

An intermediate adapter includes a first terminal operable to be electrically connected to a lens detecting terminal provided on the camera body when the intermediate adapter is attached to the camera body, a second terminal operable to be electrically connected to a terminal provided on the interchangeable lens for providing a ground potential when the interchangeable lens is attached to the intermediate adapter, and a first switch interposed between the first terminal and the second terminal. The first switch is operable to electrically connect the first terminal and the second terminal when the first switch is on, and disconnect the electrical connection between the first terminal and the second terminal when the first switch is off. While the intermediate adapter is being attached to the interchangeable lens, the first switch is off to disconnect the electrical connection between the first terminal and the second terminal.

BACKGROUND

1. Technical Field

The technical fields relates to an intermediate adapter used for usingan interchangeable lens which is not directly fitted to a camera body,that is to be interposed between the camera body and the interchangeablelens.

2. Related Art

In order to use an interchangeable lens that is not directly fitted to acamera body, an intermediate adapter that is interposed between thecamera body and the interchangeable lens has been known. Theintermediate adapter is used in such a way that the intermediate adapteris first attached to the camera body and then the interchangeable lensis attached to the intermediate adapter. The intermediate adapter isprovided with terminals corresponding to the respective signalterminals, power-supply terminals and the like of the camera body andthe interchangeable lens. Communication between the camera body and theinterchangeable lens are conducted through the terminals of theintermediate adapter.

JP-A-07-234432 discloses structure of an intermediate adapter includinga CPU as one aspect of the intermediate adapter. In the camera systemdisclosed in JP-A-07-234432, although the intermediate adapter has theCPU, the communication between the camera body and the interchangeablelens is conducted not through the CPU. Therefore, since no communicationdelay is raised and the structure of the intermediate adapter becomessimpler. The CPU in the intermediate adapter communicates with a CPU inthe camera body by using a three-wire serial method so that correctiondata are transmitted to the CPU of the camera body.

After the interchangeable lens is attached to the camera body throughthe intermediate adapter interposed therebetween, power-supply voltageis supplied from the camera body to the interchangeable lens through theintermediate adapter. However, when the power-supply voltage is suppliedfrom the camera body to the interchangeable lens while attaching theinterchangeable lens to the camera body, the power-supply voltage iserroneously supplied to terminals other than the power-supply terminals,causing a failure. Therefore, the camera body needs to supply thepower-supply voltage to the interchangeable lens after recognizing theattachment of the interchangeable lens to the adapter. Consequently, itis important to detect accurately attachment of the interchangeable lensto the adapter.

SUMMARY

To solve the above-mentioned problem, an intermediate adapter isprovided, which is capable of accurately detecting an attaching state ofthe interchangeable lens to an intermediate adapter, when attaching theinterchangeable lens to the camera body through the intermediateadapter.

In a first aspect, intermediate adapter to be interposed between acamera body and an interchangeable lens is provided. The intermediateadapter includes a first terminal operable to be electrically connectedto a lens detecting terminal provided on the camera body when theintermediate adapter is attached to the camera body, a second terminaloperable to be electrically connected to a terminal provided on theinterchangeable lens for providing a ground potential when theinterchangeable lens is attached to the intermediate adapter, and afirst switch interposed between the first terminal and the secondterminal. The first switch is operable to electrically connect the firstterminal and the second terminal when the first switch is on, anddisconnect the electrical connection between the first terminal and thesecond terminal when the first switch is off. While the intermediateadapter is being attached to the interchangeable lens, the first switchis off to disconnect the electrical connection between the firstterminal and the second terminal.

In accordance with the above-mentioned structure, while attaching theintermediate adapter to the interchangeable lens, an electricalconnection between a first terminal that is connected to a lensdetecting terminal provided on the camera body and a second terminal iscut off, thus fixing the potential of the lens detecting terminalprovided on the camera body. Therefore, while attaching the intermediateadapter to the interchangeable lens, it is possible to prevent anerroneous signal from being detected by the lens detecting terminal, andconsequently attachment of the interchangeable lens can be detectedaccurately.

In a second aspect, a camera body to which a first interchangeable lenscan be attached directly and a second interchangeable lens can beattached through an intermediate adapter is provided. The firstinterchangeable lens has a plurality of terminals disposed in a firstarrangement. The second interchangeable lens has a plurality ofterminals disposed in a second arrangement. The camera body includes aplurality of terminals disposed to be electrically connected to theplurality of terminals of the first interchangeable lens, respectively.Two adjacent terminals of the terminals of the camera body are operableto transmit a same electric signal. The intermediate adapter is operableto electrically connect the two adjacent terminals of the camera body toone of the terminals of the second interchangeable lens when theintermediate adapter is attached between the camera body and the secondinterchangeable lens.

To achieve this, the intermediate adapter includes a wiring forconnecting the two adjacent terminals of the camera body to one of thesecond terminals of the second interchangeable lens when theintermediate adapter is attached between the camera body and the secondinterchangeable lens.

In a third aspect, an imaging system including a camera body, anintermediate adapter, and an interchangeable lens that is attached tothe camera body through the intermediate adapter is provided. TheIntermediate adapter includes a first ground terminal, a second groundterminal electrically connected to the first ground terminal, a firstlens detecting terminal, and a second lens detecting terminal operableto be electrically connected to the first lens detecting terminalthrough a switch provided in the intermediate adapter. The camera bodyincludes a switch for detecting attachment of the intermediate adapterto the camera body, a grounding terminal, and a lens detecting terminal,attachment of the interchangeable lens being determined based on apotential of the lens detecting terminal of the camera body. Theinterchangeable lens includes a grounding terminal electricallyconnected to a ground potential, and a lens detecting terminalelectrically connected to a ground potential.

When the intermediate adapter is attached to the camera body, thegrounding terminal of the camera body is electrically connected to thefirst grounding terminal of the intermediate adapter and the lensdetecting terminal of the camera body is electrically connected to thefirst lens detecting terminal of the intermediate adapter. When theinterchangeable lens is attached to the intermediate adapter, the secondground terminal of the intermediate adapter is electrically connected tothe grounding terminal of the interchangeable lens and the second lensdetecting terminal of the intermediate adapter is electrically connectedto the lens detecting terminal of the interchangeable lens. While theintermediate adapter is being attached to the interchangeable lens, theswitch provided in the intermediate adapter disconnects an electricalconnection between the first lens detecting terminal and the second lensdetecting terminal of the intermediate adapter.

In accordance with the aforementioned aspects, upon attaching aninterchangeable lens to an intermediate adapter, attachment of theinterchangeable lens to the intermediate adapter can be detectedaccurately.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing a structure of an imaging system with nointermediate adapter inserted.

FIG. 2 is a front view showing a mount of the camera body.

FIG. 3 is a view showing a structure of an imaging system with anintermediate adapter of one embodiment inserted.

FIG. 4 is a front view showing a mount on the intermediate adapter side.

FIGS. 5A and 5B are views for comparing the mount of the camera bodywith the mount of the intermediate adapter.

FIG. 6 is a wiring diagram of an imaging system with the intermediateadapter of embodiment 1.

FIG. 7 is a wiring diagram of an imaging system with an intermediateadapter of embodiment 2.

FIGS. 8A to 8C are explanatory views indicating operations relating tovarious attachment statuses between various kinds of switches and pinsfor detecting attachment status among a camera body, an intermediateadapter and an interchangeable lens, in accordance with embodiment 3.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS Embodiment 1 1. Structure

FIG. 1 is a schematic view showing an imaging system with aninterchangeable lens 250 directly attached to a camera body 100. A mount101 used for attaching the interchangeable lens 250 in a bayonet systemis provided on the camera body 100. Here, the interchangeable lens 250is a lens directly mountable to the camera body 100.

FIG. 2 is a view showing the mount 101 of the camera body 100 viewedfrom the front side. The interchangeable lens 250 directly mountable tothe camera body 100 can be directly attached to the camera body 100 byinserting a claw (not shown) formed on a joining portion 253 (seeFIG. 1) of the interchangeable lens 250 into a cut-out portion 102 ofthe mount 101 of the camera body 100 and rotating the lens 250clockwise. Terminals 150 for communicating with the interchangeable lens250 are provided on the mount 101 of the camera body 100.

Here, when the shape of the joining portion (203) of the interchangeablelens does not match the mount 101 of the camera body 10, theinterchangeable lens, as it is, is not attachable to the camera body100. Moreover, the camera body 100 controls the focusing lens, diaphragmand the like (not shown) of the interchangeable lens by communicatingwith the interchangeable lens. Consequently, even when the shape of thejoining portion (203) of the interchangeable lens matches the mount 101of the camera body 100, if the specification of the terminals of theinterchangeable lens for communicating with the camera body 100 does notmatch the specification of terminals 150 of the camera body 100, thecamera body 100 fails to control the focusing lens, the diaphragm andthe like of the interchangeable lens, even though the interchangeablelens can be mechanically attached thereto. The present embodimentprovides an intermediate adapter that can eliminate such a mechanicaland electrical mismatch between the camera body 100 and theinterchangeable lens.

FIG. 3 shows an imaging system with a interchangeable lens 200 which isnot directly mountable to a camera body 100 being attached to the camerabody 100 through an intermediate adapter 300 of the present embodiment.

The camera body 100 includes a body microcomputer 104 for controllingoperations of the entire imaging system. The interchangeable lens 200includes a lens microcomputer 204 for controlling operations of theinterchangeable lens 200. The body microcomputer 104 and the lensmicrocomputer 204 communicate with each other.

A joining portion 303 which is similar to the joining portion 253 of theinterchangeable lens 250 is formed on the side of the intermediateadapter 300 that is to be attached to the camera body 100. The shape ofthe joining portion 303 of the intermediate adapter 300 is formed to bea shape matched with the mount 101 of the camera body 100. Therefore,the intermediate adapter 300 can be attached to the camera body 100 byinserting a claw (not shown) formed on the joining portion 303 of theintermediate adapter 300 into the cut-out portion 102 of the mount 101of the camera body 100 and rotating the lens 100 clockwise.

On the side of the intermediate adapter 300 at which the interchangeablelens 200 is attached, a mount 301 is formed, the mount 301 having ashape which matches the joining portion 203 of the interchangeable lens200 but is different from the shape of the mount 101 of the camera body100. With this arrangement, the interchangeable lens 200 which is notdirectly mountable to the mount 101 of the camera body 100 can beattached to the intermediate adapter 300.

FIG. 4 is a view that shows the mount 301 of the intermediate adapter300 viewed from the front side (the camera body attaching side). Theshape of the joining portion 203 of the interchangeable lens 200 matchesthe mount 301 of the intermediate adopter 300. Therefore, theinterchangeable lens 200 can be attached to the intermediate adapter 300by inserting a claw (not shown) formed on the joining portion 203 of theinterchangeable lens 200 into a cut-out portion 302 of the mount 301 ofthe intermediate adapter 300 and rotating the lens 200 clockwise.Terminals 350 for communicating with the interchangeable lens 200 areprovided on the mount 301 of the intermediate adapter 300.

As described above, the intermediate adapter 300 eliminates a mechanicalmismatch between the mount 101 of the camera body 100 and the joiningportion 203 of the interchangeable lens 200. The intermediate adapter300 makes a conversion for matching the specification of the terminalsof the interchangeable lens 200 with the specification of the terminals150 of the camera body 100, eliminating an electrical mismatch or thelike between the camera body 100 and the interchangeable lens 200.Therefore, the body microcomputer 104 built in the camera body 100communicates with the lens microcomputer 204 built in theinterchangeable lens 200 to control the focusing lens, the diaphragm andthe like of the interchangeable lens 200.

2. Wiring

FIGS. 5A and 5B are views for comparing the mount 101 of the camera body100 with the mount 301 of the intermediate adapter 300. FIG. 5A is aview showing the shape of the mount 101 of the camera body 100 and namesof respective terminals 151 to 161. FIG. 5B is a view showing the shapeof the mount 301 of the intermediate adapter 300 and names of respectiveterminals 351 to 359. The cut-out portion 102 of the mount 101 of thecamera body 100 and the cut-out portion 302 of the mount 301 of theintermediate adapter 300 are different from each other in their sizesand positions. Moreover, the terminals 151 to 161 of the mount 101 ofthe camera body 100 and the terminals 351 to 359 of the mount 301 of theintermediate adapter 300 are different from each other in their numbersand positions. The intermediate adapter 300 eliminates theabove-mentioned mechanical and electrical mismatches between the mount101 of the camera body 100 and the joining portion 203 of theinterchangeable lens 200.

The following description will discuss the terminals 151 to 161 of themount 101 of the camera body 100 and the terminals 351 to 359 of themount 301 of the intermediate adapter 300 shown in FIGS. 5A and 5B. BVCC151 and LVCC 351 are power supply terminals by which power is suppliedto the interchangeable lens 200 from the camera body 100 through theintermediate adapter 300. Moreover, BGND 152, BGND 153 and LGND 352 aregrounding terminals. Two grounding terminals BGND 152 and BOND 153 areprovided to the camera body 100 and only one grounding terminal isprovided to the interchangeable lens 200, and thus only one groundingterminal, that is, LGND 352, is provided to the intermediate adapter300. The BGND 152 and BGND 153 are combined into one terminal in theintermediate adapter 300 and then connected to LGND 352.

BDET 154 and LDET 354 are detection terminals for detecting attachmentof the interchangeable lens 200. BRST 155 and LRST 355 are resetterminals for resetting the interchangeable lens 200 by the camera body100. BBHS 156, BLHS 157, LBHS 356 and LLHS 357 are hand-shake terminalsfor communication between the camera body 100 and the interchangeablelens 200. BDIO 158, BCLK 159, LDIO 358 and LCLK 359 are terminals forcommunication between the camera body 100 and the interchangeable lens200 in a two-wire serial system. BDIO 158 and LDIO 358 are dataterminals, and BCLK 159 and LCLK 359 are clock terminals. BAHS 160 andLAHS 360 are hand-shake terminals for communication between the camerabody 100 and accessories. BAUX 161 is an auxiliary terminal, which isopen in the intermediate adapter 300 since it is not used in theinterchangeable lens 200. Therefore, there is no terminal correspondingto BAUX 161 in the mount 301 of the intermediate adapter 300.

FIG. 6 is a wiring diagram of an imaging system with an interchangeablelens 200 which is not directly mountable to the camera body 100 beingattached to the camera body 100 through the intermediate adapter 300 ofthe present embodiment.

As shown in FIG. 6, the intermediate adapter 300 includes wiresconnecting the respective terminals of the camera body 100 to thecorresponding terminals of the interchangeable lens 200.

The camera body 100 is provided with a power supply circuit 105. Theoutput of the power supply circuit 105 is supplied to the bodymicrocomputer 104 and the other blocks (not shown) in the camera body100, and is also supplied to the lens microcomputer 204 and the otherblocks (not shown) in the interchangeable lens 200 through BVCC 151 andLVCC 351. BGND 152 and BGND 153 are grounded in the camera body 100, arealso combined into one line by the wiring in the intermediate adapter300, and then connected to LGND 352 to also be grounded in theinterchangeable lens 200.

Although the camera body 100 has the two grounding terminals BGND 152and BGND 153, the interchangeable lens 200 has only one groundingterminal corresponding to those terminals, that is, LGND 352. In thiscase, the grounding terminals BGND 152 and BGND 153 of the camera body100 are preferably provided adjacently. For example, when BGND 153 isprovided adjacent to BAUX 161, in order to combine BGND 152 and BGND 153with each other to form one line in the intermediate adapter 300, itneeds to make a wire from BDET 154 to BAHS 160 intersect with a wire ofBGND 153. To do so, at least two layers of flexible substrates arerequired, causing a high cost in the intermediate adapter 300. Incontrast, when BGN 152 and BGND 153 are provided adjacently, the wiringof the intermediate adapter 300 can be achieved by using a single layerof the flexible substrate. Here, in place of providing the two groundingterminals, BGND 152 and BGND 153, adjacently, BGND 153 may be opened inthe intermediate adapter 300. In this case, the wiring of theintermediate adapter 300 can be achieved by using a single layer of theflexible substrate. However one end of the wiring is kept open, and thisis not a desirable state from electrical viewpoint.

BDET 154 is connected to BVCC 151 through a resistor 110 Therefore, in astate where no intermediate adapter 300 is attached to the camera body100, the body microcomputer 104 detects an “H” (High: a high potentialin the signal line) of BDET 154. BDET 154 is connected to LDET 354through a switch 306 in the intermediate adapter 300. A pin 307 isdesigned in a manner so as to move by contact with a portion of the mainbody of the interchangeable lens 200 to open/close (ON/OFF) the switch306. More specifically, the pin 307 is configured so as to open theswitch 306 when no interchangeable lens 200 is attached to theintermediate adapter 300 and to close the switch 306 when theinterchangeable lens 200 is attached to the intermediate adapter 300.Therefore, in a state where the intermediate adapter 300 is attached tothe camera body 100 but no interchangeable lens 200 is attached to theintermediate adapter 300, the switch 306 is opened so that the bodymicrocomputer 104 detects an “H” of BDET 154. In contrast, in a statewhere the intermediate adapter 300 is attached to the camera body andthe interchangeable lens 200 is attached to the intermediate adapter300, the switch 306 is closed to ground LDET 354 in the interchangeablelens 200. Thus the body microcomputer 104 detects an “L” (Low: a lowpotential in the signal line) of BDET 154.

Each of BRST 155, BBHS 156, BLHS 157, BDIO 158, BCLK 159 and BAHS 160 isconnected to the corresponding terminal in the intermediate adapter 300,that is, each of LRST 355, LBHS 356, LLHS 357, LDIO 358, LCLK 359 andLAHS 360, respectively. LAHS 360 is not used in the interchangeable lens200, and thus it is opened in the interchangeable lens 200. Moreover,BAUX 161 is not used in the interchangeable lens 200, and thus it isopened in the intermediate adapter 300.

The camera body 100 is provided with a switch 106 one end of which isgrounded through a resistor 127 and the other end of which is connectedto BVCC 151. The opening/closing operation (ON/OFF) of the switch 106 iscarried out by a pin 107. The pin 107 is designed to move by contactwith a portion of the main body of the intermediate adapter 300 so as tocarry out the opening/closing operations (ON/OFF) of the switch 106.More specifically, the pin 107 is designed so as to open the switch 106when no intermediate adapter 300 is attached to the camera body 100, andto close the switch 106 when the intermediate adapter 300 is attached tothe camera body 100. Therefore, in a state where no intermediate adapter300 is attached to the camera body 100, the switch 106 is opened,causing the body microcomputer 104 to detect an “L” of ADET 170. Incontrast, in a state where the intermediate adapter 300 is attached tothe camera body 100, the switch 106 is closed, causing the bodymicrocomputer 104 to detect a “High” of ADET 170. In this manner, ADET170 is used for detecting attachment of the intermediate adapter 300 tothe camera body 100. The switch 106 and the pin 107 are one example ofan attachment detection unit for detecting attachment of the adapter tothe camera body 100.

Here, in order to prevent the body microcomputer 104 and the lensmicrocomputer 204 from being broken due to external noise, such asstatic electricity, all the terminals are grounded through zener diodes131 to 138 and 232 to 236. Resistors 110 to 118 and resistors 212 to 216are damping resistors for reducing an abrupt change in signals tosuppress noise. Resistors 124 and 125 as well as resistors 222, 223, 225and 226 are protective resistors that protect input terminals orinput/output terminals. In FIG. 6, the directions of the respectivesignals are indicated by arrows.

In the above explanation, each of the detection of attachment of theintermediate adapter 300 to the camera body 100 and the detection ofattachment of the interchangeable lens 200 to the intermediate adapter300 is supposed to be carried out by using a pin and a switch. However,the embodiment is not limited by this arrangement. Instead of themechanical detection method, an optical detection method by using aphoto-interrupter or the like and a magnetic detection method by using aHail element may be adopted. These detection methods require fewermovable units in comparison with the mechanical detection method, thusimproving the reliability and durability.

3. Operations

By using the intermediate adapter 300 constructed and wired as describedabove, the body microcomputer 104 can detect attachment of theintermediate adapter 300 and the interchangeable lens 200 step by step.Table 1 shows detection status of ADET 170 and BDET 154 by the bodymicrocomputer 104 in association with attachment states of theintermediate adopter 300 and the interchangeable lens 200.

TABLE 1 ADET BDET no intermediate adapter attached L H intermediateadapter attached H H (with no interchangeable lens attached)intermediate adapter attached and H L interchangeable lens attached

When no intermediate adapter 300 is attached to the camera body 100, thebody microcomputer 104 detects an “L” of ADET 170. Moreover, in the casewhere no intermediate adapter 300 is attached to the camera body 100, nointerchangeable lens 200 is of course attached thereto, and thus thebody microcomputer 104 detects an “H” of BDET 154. Consequently, whenADET 170 is in “L” and BDET 154 is in “H”, it is recognized that nointermediate adapter 300 is attached to the camera body 100.

When the intermediate adapter 300 is attached to the camera body but nointerchangeable lens 200 is attached to the intermediate adapter 300,the body microcomputer 104 detects “H” of ADET 170 and “H” of BDET 154.Therefore, when ADET 170 is in “H” and BDET 154 is in “H”, it isrecognized that the intermediate adapter 300 is attached to the camerabody 100 but no interchangeable lens 200 is attached the intermediateadapter 300.

When the intermediate adapter 300 is attached to the camera body 100 andthe interchangeable lens 200 attached to the intermediate adapter 300,the body microcomputer 104 detects “H” of ADET 170 and “L” of BDET 154.Therefore, when ADET 170 is in “H” and BDET 154 is in “L”, it isrecognized that the intermediate adapter 300 is attached to the camerabody 100 and the interchangeable lens 200 is also attached to theintermediate adapter 300.

Embodiment 2

FIG. 7 shows another example of structure (wiring diagram) of an imagingsystem. The intermediate adapter 300 and the camera body 100 shown inFIG. 7 differ from those in the structure shown in FIG. 6 of embodiment1 in structure relating to the switch 106 and the pin 107 for detectingattachment of the adapter. More specifically, in the structure of FIG.7, the switch 106 and the pin 107 for detecting attachment of theadapter are removed from the camera body 100 in the structure shown inFIG. 6, and in place of these, a switch 308 and a pin 309 for detectingattachment of the adapter are installed in the intermediate adapter 300.Here, a detection unit related to BDET 154 includes a switch 306 and apin 307 in the same manner as in the structure shown in FIG. 6.Moreover, a terminal (not shown) on the intermediate adapter 300 sidefor BDET 154 and a terminal (not shown) on the intermediate adapter 300side for ADET 170 form one example of an informing unit. The otherstructures are the same as those of embodiment 1 (structures shown inFIG. 6), and the description thereof will be omitted.

In the structure shown in FIG. 7, ADET 170 is a terminal to be connectedto the intermediate adapter 300, and is exposed to the outside of thecamera body 100. Therefore, in order to prevent damages to the bodymicrocomputer 104 due to external noise, such as static electricity,this is grounded through a zener diode 139.

The switch 308 provided in the intermediate adapter 300 has its one endconnected to LVCC 351 and the other end connected to ADET 170. The pin309 is configured so as to open the switch 308 when no intermediateadapter 300 is attached to the camera body 100, and to close the switch308 when the intermediate adapter 300 is attached to the camera body100. Therefore, when no intermediate adapter 300 is attached to thecamera body 100, the switch 308 is opened and thus the bodymicrocomputer 104 detects “L” of ADET 170. In contrast, when theintermediate adapter 300 is attached to the camera body 100, the switch308 is closed and thus the body microcomputer 104 detects “H” of ADET170.

With this arrangement, the camera body 100 is no longer required to havethe switch 106 and the pin 107, it becomes possible to cut costs of thecamera body 100. Here, the detection status of ADET 170 and BDET 154 bythe body microcomputer 104 in association with the attachment status ofthe intermediate adopter 300 and the interchangeable lens 200 are thesame as those shown in Table 1, the description thereof is omitted.

Embodiment 3

Embodiments 1 and 2 have explained the structure capable of detectingthe attachment or not-attachment of the adapter 300 and theinterchangeable lens 200 to the camera body 100. The present embodimentwill discuss a structure for preventing an erroneous detection during anoperation for attaching the intermediate adapter 300 and theinterchangeable lens 200.

The structure of the imaging system of the present embodiment isbasically the same as that explained in embodiment 1, however, itdiffers from embodiment 1 in operations of the switch 106 and the switch306. Referring to FIG. 8, the following description will discuss theoperations of the switch 106 and the pin 107 of the present embodiment.

FIG. 8A is a view showing status of the switch 106 and the pin 107 whenno intermediate adapter 300 is attached to the camera body 100. FIG. 8Bis a view showing status of the switch 106 and the pin 107 while theintermediate adapter 300 is being attached to the camera body 100. FIG.8C is a view showing status of the switch 106 and the pin 107 uponcompletion of attaching the intermediate adapter 300 to the camera body100.

As shown in FIGS. 8A to 8C, the pin 106 is biased outward from thecamera body 100 with a spring 108. The switch 106 has a protrudingportion 106 b which slides in association with the movement of pin 107.When the protruding portion 106 b is located at a position “b”, theswitch 106 is turned on. When the protruding portion 106 b is located ata position “a”, the switch 106 is turned off. A concave section A isformed on the intermediate adapter 300 or the interchangeable lens 200.When the intermediate adapter 300 or the interchangeable lens 200 isattached correctly to the attaching position of the camera body 100, thepin 107 is fitted to the concave section A. When the pin 107 is fittedto the concave section A, the protruding portion 106 b is moved to theposition “b” by the pin 107, turning on the switch 106.

As described above, when the intermediate adapter 300 is not attached tothe camera body 100, the switch 106 is on. When the intermediate adapter300 is being attached to the camera body 100, the switch 106 is off.When the operation for attaching the intermediate adapter to the camerabody 100 is completed, the switch 106 is on.

Moreover, in the present embodiment, the switch 306 and the pin 307relating to BDET provided in the intermediate adapter 300 also have thesame structure as that of the switch 106 and the pin 107 as shown inFIGS. 8A to 8B and operate in the same manner. That is, when theinterchangeable lens 200 is not attached to the intermediate adapter300, the switch 306 is on. During the operation for attaching theinterchangeable lens 200 to the intermediate adapter 300, the switch 306is off. When the operation for attaching the interchangeable lens 200 tothe intermediate adapter 300 has been completed, the switch 306 is on.

Table 2 shows detection status of ADET 170 and BDET 154 by the bodymicrocomputer 104 in association with attachment states of theintermediate adopter 300 and the interchangeable lens 200 in the presentembodiment.

TABLE 2 condition condition of switch of switch ADET BDET 106 306intermediate adapter not- H H FIG. 8A — attached during an operation forL H FIG. 8B — attaching intermediate adapter (with no interchangeablelens attached) intermediate adapter attached H H FIG. 8C FIG. 8A (withno interchangeable lens attached) during an operation for H H FIG. 8CFIG. 8B attaching interchangeable lens (with intermediate adapterattached) intermediate adapter attached, H L FIG. 8C FIG. 8Cinterchangeable lens attached

In the case where no intermediate adapter 300 is attached to the camerabody 100, the switch 106 and the pin 107 are brought into the conditionshown in FIG. 8A, so that the switch 106 is turned on and an “H” of ADET170 is detected. Since BDET 154 is connected to BVCC 151 through theresistor 110, an “H” of BDET 154 is detected.

During the operation for attaching the intermediate adapter 300 to thecamera body 100, the switch 106 and the pin 107 take the condition shownin FIG. 8B, so that the switch 106 is turned off. Consequently, ADET 170is grounded through a resistor 127, and thus “L” of ADET 170 isdetected. Here, since the connected status of BDET 154 has no change,“H” thereof is detected.

Upon completion of attaching the intermediate adapter 300 to the camerabody 100, the switch 106 and the pin 107 take the condition shown inFIG. 8C so that the switch 106 is turned on and “H” of ADET 170 isdetected. Since the connected state of BDET 154 has no change, “H”thereof is detected.

During the operation for attaching the interchangeable lens 200 to theintermediate adapter 300 which is attached to the camera body 100, theswitch 306 and the pin 307 take the condition as shown in FIG. 8B sothat the switch 306 is turned off. For this reason, BVCC 151 isconnected to BDET 154 through a resistor 151, “H” of BDET 154 isdetected. In this manner, during the operation for attaching theinterchangeable lens 200 to the intermediate adapter 300, the switch 306is forcedly turned off. With this arrangement, even when LDET terminalof the intermediate adapter 300 is made in contact with any of thevarious terminals of the interchangeable lens 200 during the attachingoperation, it is possible to prevent BDET 154 from being erroneously“L”, consequently causing the BDET signal to be kept “H”. Thus, itbecomes possible to prevent an erroneous detection of the BDET signal bythe body microcomputer 104.

Upon completion of attaching the interchangeable lens 200 to theintermediate adapter 300, the switch 306 and the pin 307 take thecondition shown in FIG. 8B so that the switch 306 is turned on. Thiscauses BDET 170 to be connected to a ground potential in theinterchangeable lens so that “L” of BDET 170 is detected.

As described above, when the ADET detection signal and BDET detectionsignal are respectively set in “H” and “L”, it can be detected that theoperation for attaching the interchangeable lens 200 to the intermediateadapter 300 is completed. With the above-mentioned method, it ispossible to prevent an erroneous detection of the completion ofattaching the interchangeable lens 200 which is caused by a change inconnecting status between terminals during the operation for attachingthe interchangeable lens 200.

Table 3 shows detection states of ADET 170 and BDET 154 by the bodymicrocomputer 104 in association with the attachment condition of aninterchangeable lens 250 when the interchangeable lens 250 is attachedto the camera body 100 without the intermediate adapter 300.

TABLE 3 condition of ADET BDET switch 106 interchangeable lens not- H HFIG. 8A attached during an operation for L — FIG. 8B attachinginterchangeable lens interchangeable lens attached H L FIG. 8C

When the interchangeable lens 200 is attached without the intermediateadapter 300, the pin 107 takes the condition as shown in FIG. 8B duringthe attaching. Then, the ADET detection signal is brought into “L”.Thus, the body microcomputer 104 can recognize that the interchangeablelens has not been attached independent of the BDET detection signal.That is, the combination of “H” and “L” as the detection status of ADET170 and BDET 154 is provided only when attaching of the interchangeablelens 250 is completed. Therefore, regardless of the use or non-use ofthe intermediate adapter 300, it is possible to surely detectattachment/non-attachment of the interchangeable lens by detecting thecombination of “H” and “L” as the detection status of ADET 170 and BDET154. By starting a power supply after the detection of the attachmentstatus of the interchangeable lens, the body microcomputer 104 makes itpossible to prevent damages to the elements in the interchangeable lens.

INDUSTRIAL APPLICABILITY

In accordance with the embodiments, since, upon attaching aninterchangeable lens through an adapter, the attachment status of theinterchangeable lens can be positively detected, it is possible to applythe system of the present embodiments to an intermediate adapter and acamera body of an imaging system of an interchangeable lens system.

Although the aforementioned description has been provided in connectionwith specified embodiments thereof, many other modifications,corrections and applications are apparent to those skilled in the art.Therefore, the embodiments are not limited by the disclosure providedherein. The present disclosure relates to subject matter contained inJapanese Patent Application No. 2008-116831, filed on Apr. 28, 2008,which is expressly incorporated herein by reference in its entirety.

1. An intermediate adapter to be interposed between a camera body and aninterchangeable lens, the intermediate adapter comprising: a firstterminal operable to be electrically connected to a lens detectingterminal provided on the camera body when the intermediate adapter isattached to the camera body; a second terminal operable to beelectrically connected to a terminal provided on the interchangeablelens for providing a ground potential when the interchangeable lens isattached to the intermediate adapter; and a first switch interposedbetween the first terminal and the second terminal, the first switchoperable to electrically connect the first terminal and the secondterminal when the first switch is on, and disconnect the electricalconnection between the first terminal and the second terminal when thefirst switch is off, wherein while the intermediate adapter is beingattached to the interchangeable lens, the first switch is off todisconnect the electrical connection between the first terminal and thesecond terminal.
 2. The intermediate adapter according to claim 1,wherein when the interchangeable lens is completely attached to theintermediate adapter, the first switch is turned on to electricallyconnect the first terminal and the second terminal.
 3. The intermediateadapter according to claim 1, wherein attachment of the intermediateadapter to the camera body is detected by a switch provided in thecamera body.
 4. The intermediate adapter according to claim 1, whereinwhen the intermediate adapter is completely attached to theinterchangeable lens, the lens detecting terminal provided on the camerabody is controlled to be at a ground potential.
 5. The intermediateadapter according to claim 1, further comprising: a third terminaloperable to be electrically connected to an adapter detecting terminalprovided on the camera body when the intermediate adapter is attached tothe camera body; and a second switch operable to electrically connectthe third terminal to a predetermined potential when the second switchis on, and disconnect the electrical connection of the third terminaland the predetermined potential when the second switch is off, whereinthe second switch changes between the on and off operations based on acontact condition between the intermediate adapter and the camera body.6. The intermediate adapter according to claim 5, wherein when theintermediate adapter is completely attached to the camera body, thesecond switch is turned on, and when the intermediate adapter is notcompletely attached to the camera body, the second switch is turned off.7. A camera body to which a first interchangeable lens can be attacheddirectly and a second interchangeable lens can be attached through anintermediate adapter, the first interchangeable lens having a pluralityof terminals disposed in a first arrangement, the second interchangeablelens having a plurality of terminals disposed in a second arrangement,the camera body comprising: a plurality of terminals disposed to beelectrically connected to the plurality of terminals of the firstinterchangeable lens, respectively, wherein two adjacent terminals ofthe terminals of the camera body are operable to transmit a sameelectric signal, and the intermediate adapter is operable toelectrically connect the two adjacent terminals of the camera body toone of the terminals of the second interchangeable lens when theintermediate adapter is attached between the camera body and the secondinterchangeable lens.
 8. The camera body according to claim 7, whereinthe terminals of the camera body include terminals corresponding to theterminals of the second interchangeable lens and a terminal which doesnot correspond to the terminals of the second interchangeable lens, theterminal of the camera body which does not correspond to the terminalsof the second interchangeable lens is disposed adjacently and outsidethe terminals which correspond to the terminals of the secondinterchangeable lens.
 9. An intermediate adapter connectable to thecamera body according to claim 7, comprising: a wiring for connectingthe two adjacent terminals of the camera body to one of the terminals ofthe second interchangeable lens when the intermediate adapter isattached between the camera body and the second interchangeable lens.10. An imaging system comprising a camera body, an intermediate adapter,and an interchangeable lens that is attached to the camera body throughthe intermediate adapter, the intermediate adapter comprising: a firstground terminal; a second ground terminal electrically connected to thefirst ground terminal; a first lens detecting terminal; and a secondlens detecting terminal operable to be electrically connected to thefirst lens detecting terminal through a switch provided in theintermediate adapter, and the camera body comprising: a switch fordetecting attachment of the intermediate adapter to the camera body; agrounding terminal; and a lens detecting terminal, attachment of theinterchangeable lens being determined based on a potential of the lensdetecting terminal of the camera body, the interchangeable lenscomprising: a grounding terminal electrically connected to a groundpotential; and a lens detecting terminal electrically connected to aground potential, wherein, when the intermediate adapter is attached tothe camera body, the grounding terminal of the camera body iselectrically connected to the first grounding terminal of theintermediate adapter and the lens detecting terminal of the camera bodyis electrically connected to the first lens detecting terminal of theintermediate adapter, when the interchangeable lens is attached to theintermediate adapter, the second ground terminal of the intermediateadapter is electrically connected to the grounding terminal of theinterchangeable lens and the second lens detecting terminal of theintermediate adapter is electrically connected to the lens detectingterminal of the interchangeable lens, and while the intermediate adapteris being attached to the interchangeable lens, the switch provided inthe intermediate adapter disconnects an electrical connection betweenthe first lens detecting terminal and the second lens detecting terminalof the intermediate adapter.
 11. The imaging system according to claim10, wherein while the intermediate adapter is being attached to thecamera body, the switch provided in the camera body detects that theintermediate adapter is not attached to the camera body, and when theintermediate adapter is attached to the camera body, the switch providedin the camera body detects that the intermediate adapter is attached tothe camera body.
 12. The imaging system according to claim 11, whereinthe switch provided in the camera body is operable to detect whether ornot the intermediate adapter is attached to the camera body by beingturned on and off by a pin, the pin being operable to move by contactwith a portion of a main body of the intermediate adapter such that theswitch is turned on by the pin when the intermediate adapter iscompletely attached to the camera body and the switch is turned off bythe pin when the intermediate adapter is not completely attached to thecamera body.